Re: [Qemu-devel] [PATCH] fix qemu_malloc() error check for size==0

[malc]

On Mon, 18 May 2009, Eduardo Habkost wrote:

> This patch is similar to a previous qemu_realloc() fix
> (commit 322691a5c9f1c8531554148d47c078b5be590805), but for qemu_malloc().
> 
> malloc(0) may correctly return NULL if size==0. We don't want to abort qemu on
> this case.

Only it wouldn't (on Linux):

$ cat malloc.c
#include <stdlib.h>

int main (void)
{
    printf ("%p\n", malloc (0));
    return 0;
}
$ gcc malloc.c
$ ./a.out 
0x10011008

Standard (in 7.20.3) says that malloc's behaviour in case of size being
zero is implementation defined.

Try `git show 63c75dcd669d011f438421980b4379827da4bb1c'.

The best(only?) thing to do is to check size passed to qemu_malloc[z]
and abort the program if this situation is encountered.

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